# ERPs analysis

**URL:** <https://mne.discourse.group/t/erps-analysis/2382>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [November 19, 2020, 3:45pm UTC](https://mne.discourse.group/t/erps-analysis/2382 "2020-11-19T15:45:40Z")\
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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [November 19, 2020, 3:45pm UTC](https://mne.discourse.group/t/erps-analysis/2382/1 "2020-11-19T15:45:40Z")

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Dear all,

I am using MNE python to analyse EEG data and we want to do an ERPs analysis. After visualizing the data (by plotting the participants' grand average of the evokeds for each condition), I need to extract the values of the amplitude (area under the curve) of specific potentials in specific time windows we selected. I am using the function np.trapz on the selected time intervals. However, I am not sure whether this approach is valid or whether there are other alternatives to be considered. Moreover, it seems like the pattern we find only by visualising the data, doesn't match the statistics we run on the data, thus we were wondering whether we are extracting the data in the right way (via the np.trapz function).

Thank you for your help.

Chiara  
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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [November 24, 2020, 7:56am UTC](https://mne.discourse.group/t/erps-analysis/2382/2 "2020-11-24T07:56:20Z")

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hi Chiara,

I am using MNE python to analyse EEG data and we want to do an ERPs

> analysis. After visualizing the data (by plotting the participants' grand  
> average of the evokeds for each condition), I need to extract the values of  
> the amplitude (area under the curve) of specific potentials in specific  
> time windows we selected. I am using the function np.trapz on the selected  
> time intervals. However, I am not sure whether this approach is valid or  
> whether there are other alternatives to be considered.

I would have used scipy.integrate.quad but I doubt it would lead to a big  
difference.

it's hard to say more without looking at the data

HTH  
Alex

> Moreover, it seems like the pattern we find only by visualising the data,  
> doesn't match the statistics we run on the data, thus we were wondering  
> whether we are extracting the data in the right way (via the np.trapz  
> function).
> 
> Thank you for your help.
> 
> Chiara  
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